Processing of clinker containing polymetallic raw materials

Abstract

Disclosed are methods and systems for processing clinker containing iron and non-ferrous metals for extraction of those metals. The processing comprises pretreatment of clinker resulting in a removable carbon-containing foam phase, forming a metal-containing cake. Melting of the cake is then performed in the absence of air delivery and in the presence of carbon, resulting in phases of slag, metal, and matte. Melting may occur while maintaining a mass ratio of iron to carbon of no greater than 14:1, such that cast iron forms instead of sponge iron. The metal and matte phases, containing non-ferrous metals and iron, are then exposed to further dissolution, filtration, and salting out to extract the non-ferrous metals and iron. Byproducts of various stages of the process are also recycled into earlier stages or further processed to extract additional copper, iron, and other non-ferrous metals.

What is claimed is: 
     
         1 . A method for processing zinc production clinker, comprising:
 providing a clinker from zinc production, said clinker comprising sulfur, carbon, iron, and non-ferrous metals,   pretreating said clinker in a solution, said solution comprising one or more inorganic acids, said pretreating resulting in a pulp having a floating foamy part, wherein said floating foamy part is removed from said pulp,   filtering said pulp, said filtering resulting in a first product comprising a cake and a second product comprising a first filtrate, wherein said second product is separated from said first product, wherein said first product is dried, and   melting said first product within a furnace, said melting resulting in a formation of a slag phase, a matte phase, a metal phase, and a gas phase, wherein the melting of said matte and metal phases occurs in an absence of any air delivery and in a presence of carbon, wherein said matte phase and said metal phase share a distribution of iron and non-ferrous metals.   
     
     
         2 . The method of  claim 1 , wherein said melting is performed while maintaining a mass ratio of iron to carbon of not greater than 14:1 within the furnace, such that said metal phase comprises more cast iron than sponge iron. 
     
     
         3 . The method of  claim 1 , wherein up to 80 percent of the carbon in the clinker is removed during said pretreating via removal of said floating foamy part from said pulp. 
     
     
         4 . The method of  claim 1 , further comprising:
 dissolving said matte phase and said metal phase together in a solution, said solution comprising sulfuric acid, forming a metal-matte solution, and   filtering said metal-matte solution to separate non-ferrous metals from said metal-matte solution, thus forming a second filtrate.   
     
     
         5 . The method of  claim 4 , further comprising:
 salting out of iron sulphate from the second filtrate, said salting out comprising adding a solution of 96% sulfuric acid by weight to said second filtrate.   
     
     
         6 . The method of  claim 1 , wherein the absence of any air delivery is caused by a formation of a slag layer on a furnace surface, said slag layer blocking any access of air to said metal and matte phases located beneath said slag layer. 
     
     
         7 . The method of  claim 1 , wherein said solution comprising one or more inorganic acids comprises 49% sulfuric acid by weight. 
     
     
         8 . The method of  claim 7 , wherein said second product comprising a first filtrate is further processed with hydrogen sulfide to form a deposition of copper in a sulphidic form and a third filtrate, and further comprising salting out of iron sulphate from the third filtrate, said salting out comprising adding a solution of 96% sulfuric acid by weight to said third filtrate. 
     
     
         9 . The method of  claim 8 , wherein said hydrogen sulfide is a byproduct produced from a dissolving of said matte phase and said metal phase together in a solution, said solution comprising sulfuric acid. 
     
     
         10 . The method of  claim 1 , wherein calcium oxide (CaO) is added to said first product comprising a cake during melting, said calcium oxide having a mass ratio to iron, Ca:Fe, of 1:1 within the furnace. 
     
     
         11 . The method of  claim 1 , wherein said non-ferrous metals are copper, lead, silver, and gold. 
     
     
         12 . A method for processing zinc production clinker, comprising:
 providing a clinker from zinc production, said clinker comprising sulfur, iron, carbon, and non-ferrous metals,   melting said clinker in a furnace, said melting resulting in a formation of a slag phase, a matte phase, a metal phase, and a gas phase, wherein the melting of said matte and metal phases occurs in an absence of any air delivery and in a presence of carbon,   wherein said melting is performed while maintaining a mass ratio of iron to carbon of not greater than 14:1, wherein said matte phase comprises a majority of said non-ferrous metals and said metal phase comprises a majority of said iron.   
     
     
         13 . The method of  claim 12 , further comprising:
 dissolving said matte phase and said metal phase together in a solution, said solution comprising sulfuric acid, forming a metal-matte solution, and   filtering said metal-matte solution to separate non-ferrous metals from said metal-matte solution, thus forming a filtrate, said filtrate comprising iron.   
     
     
         14 . The method of  claim 13 , further comprising:
 salting out of iron sulphate from the filtrate, said salting out comprising adding a solution of 96% sulfuric acid by weight to said filtrate.   
     
     
         15 . The method of  claim 12 , where said melting occurs at 1250-1350 degrees Celsius. 
     
     
         16 . The method of  claim 12 , wherein said metal phase comprises cast iron. 
     
     
         17 . The method of  claim 12 , wherein said metal phase comprises more cast iron than sponge iron. 
     
     
         18 . The method of  claim 17 , wherein said metal phase contains no sponge iron. 
     
     
         19 . A system for processing zinc production clinker, comprising:
 a supply unit for providing a clinker from zinc production, said clinker comprising sulfur, carbon, iron, and non-ferrous metals,   a pretreatment unit for pretreating said clinker in a solution, said solution comprising one or more inorganic acids, said pretreating resulting in a pulp having a floating foamy part, wherein said floating foamy part is removed from said pulp,   a pulp filtration unit for filtering said pulp, said filtering resulting in a first product comprising a cake and a second product comprising a first filtrate, wherein said second product is separated from said first product, wherein said first product is dried, and   a furnace for melting said first product within the furnace, said melting resulting in a formation of a slag phase, a matte phase, a metal phase, and a gas phase, wherein the melting of said matte and metal phases occurs in an absence of any air delivery and in a presence of carbon, wherein said matte phase and said metal phase share a distribution of iron and non-ferrous metals.   
     
     
         20 . The system of  claim 19 , wherein said melting is performed while maintaining a mass ratio of iron to carbon of not greater than 14:1 within the furnace, such that said metal phase comprises more cast iron than sponge iron.